Breast Scanner Has Potential for Diagnosing Cancer Earlier

A unique new device, the dual modality tomographic (DMT) breast scanner, has shown in its pilot study the ability to pinpoint to a much finer degree the precise location of breast masses, and more importantly, to differentiate between cancerous and harmless lesions accurately.

A pilot clinical study, led by Mark B. Williams, Ph.D., associate professor of radiology, biomedical engineering and physics at the University of Virginia (UVA; Charlottesville, USA), was published in the April 2010 issue of the journal Radiology. The DMT breast scanner, developed by UVA researchers, works by combining two cutting-edge imaging methods, one that obtains three-dimensional (3D) anatomic (structural) imaging and another that obtains 3D biologic (functional) imaging, into one integrated device. The machine runs the scans sequentially, obtaining both types of images with the breast in the same, immobilized position.

"Using the most current breast imaging methods, only about one in four of all biopsied breast lesions are actually malignant--that is, the positive predictive value is about 25%--so there's a great deal of room for improved imaging diagnostic capabilities,” said Dr. Williams. "Our pilot study indicates promising results toward reducing the number of false-positive imaging diagnoses, which would therefore eliminate many unnecessary biopsies.”

The scanner also is especially useful in revealing pathology in women with radiographically dense breasts. The millions of women with thicker than average breast tissue or fibrous breasts continue to present a daunting diagnostic challenge for current breast imaging methods.

Such was the case with one patient who has fibrocystic disease and several years ago had undergone two needle biopsies (with normal results). Most recently, her physician had found yet another suspicious area on her mammogram and scheduled her for a breast biopsy, which came back normal negative for cancer. Moreover, the results of these new, unique images told a different story for she had very early-stage breast cancer. The hybrid scanner used to detect the patient's cancer combines 3D digital X-ray breast tomosynthesis together with 3D molecular breast imaging tomosynthesis, a recently developed technique that uses intravenously injected compounds (tracers) that are absorbed to a much greater degree by malignant lesions than benign ones. A special camera positioned in close proximity to the breast then performs functional imaging of the entire breast, while the digital X-ray tomosynthesis obtains coregistered structural images.

In this case, the tracers targeted exactly where the tiny, malignant mass was concealed in the midst of a particularly radiodense region of her breast. "Despite using the latest clinically available imaging technologies and the most expert radiologists, breast cancers are still missed, especially in women with radiodense breasts,” stated Dr. Williams. "This is why our research is so important for patients.”

But as Dr. Williams pointed out, this pilot clinical study of the 17 women tested could have far greater implications. "Our early results show that the DMT scanner is a feasible and accurate method for detecting and diagnosing breast cancer. In our study, we not only were able to detect a missed cancerous lesion but we also corroborated every single benign diagnosis from biopsy results. These findings demonstrate an obvious need for larger studies to further prove the efficacy of this new device,” Dr. Williams concluded.

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